Supro 1688TN replacement knobs

[Lull]

Hi All,

This is my first post. I found this amazing forum yesterday while searching for a replacement handle for my Supro 1688TN, which I did find on the Ohio Travel Bag website thanks to the info on this forum. Anyhow, I bought a 1960's Supro 1688TN amplifier for about 15 years ago and it had chicken head knobs on it. I'd like to replace them with knobs that look like the original ones, which I believe were made by Rogan Bros (the silver top knob shown in the attached picture). I haven't found any suitable replacement so far; and the new Supro amps knobs won't fit because they are press-on type.

Any help in finding knobs that look similar would be highly appreciated.

Thanks!

[Mick Bailey]

Hi and welcome to the forum.

I've converted push-on knobs to 1/4" screw-type by machining up a brass insert and epoxying this in place. The centre boss of the new knob needs to be removed to do this. Usually they Dremel out just fine. I knurl the outside of the bush and after the adhesive has set drill and tap for the screw using a simple hardwood alignment jig in a drill press. Then use a commercial grub screw. It works perfectly, but depends on what you have available to you and your skill levels (and patience).

At a push you could do this without a lathe. You can even break open some chicken-head knobs that already have a bush fitted - then you have the complete screw and knurled or milled bush assembly and just need to set this in epoxy or kneadable epoxy putty. Then you only need to drill the cross-hole through the plastic.

Just take care not to mark or otherwise damage the knobs.

[Lull]

Hi and welcome to the forum.

I've converted push-on knobs to 1/4" screw-type by machining up a brass insert and epoxying this in place. The centre boss of the new knob needs to be removed to do this. Usually they Dremel out just fine. I knurl the outside of the bush and after the adhesive has set drill and tap for the screw using a simple hardwood alignment jig in a drill press. Then use a commercial grub screw. It works perfectly, but depends on what you have available to you and your skill levels (and patience).

At a push you could do this without a lathe. You can even break open some chicken-head knobs that already have a bush fitted - then you have the complete screw and knurled or milled bush assembly and just need to set this in epoxy or kneadable epoxy putty. Then you only need to drill the cross-hole through the plastic.

Just take care not to mark or otherwise damage the knobs.

Hi,

Thank you for the good idea and for taking the time to share your experience; it's really appreciated. I'll probably go that route since I'm pretty convinced I won't find suitable replacement knobs that will be plug-and-play.